[pygobject] Override Gtk.TreeSortable.get_sort_column_id to not return success value

[Sebastian Polsterl <sebp src gnome org>]

commit 80b1b266fa68a5c67106871502017166628f71e4
Author: Sebastian Pölsterl <sebp k-d-w org>
Date:   Sat Oct 23 14:20:38 2010 +0200

    Override Gtk.TreeSortable.get_sort_column_id to not return success value

 gi/overrides/Gtk.py |   12 ++++++++++++
 1 files changed, 12 insertions(+), 0 deletions(-)
---
diff --git a/gi/overrides/Gtk.py b/gi/overrides/Gtk.py
index 088369d..1d3be32 100644
--- a/gi/overrides/Gtk.py
+++ b/gi/overrides/Gtk.py
@@ -769,6 +769,18 @@ class TreeStore(Gtk.TreeStore, TreeModel):
 TreeStore = override(TreeStore)
 __all__.append('TreeStore')
 
+class TreeSortable(Gtk.TreeSortable):
+
+    def get_sort_column_id(self):
+        success, sort_column_id, order = super(TreeSortable, self).get_sort_column_id()
+        if success:
+            return (sort_column_id, order,)
+        else:
+            return (None, None,)
+
+TreeSortable = override(TreeSortable)
+__all__.append('TreeSortable')
+
 class TreeViewColumn(Gtk.TreeViewColumn):
     def __init__(self, title='',
                  cell_renderer=None,